Blisks

Non-Contact Measurement of Blisk Aerofoils and Gas Path Features

Blisk is a portmanteau of ‘bladed disc’ and describes a one-piece rotor on the compressor side of a gas turbine. A blisk has fewer components than a conventional blade and disc assembly, and offers lower weight and drag. Because they eliminate high-drag blade locators and fixings, blisks can give an 8% effi ciency increase. Blisks were first produced in the 1980s for the T700 engine used in Black Hawk and Apache helicopters, and are now a mainstay of military and civil aeroengines. The functional features of blisks are the locators and fixing holes on the disc, and the surface profile and location of each blade. To prevent unwanted resonances and imbalance, it is important that these features are aligned to each other.